Exile Tribute: The Amiga conversions

The artwork from the AGA and CD32 version>

The Commodore Amiga was a 16-bit machine released a couple of years I believe before Exile was released for the BBC. Along with the ageing C64, it was extremely popular and even today there is a large user base judging by the presence of Amiga newstand magazines. It is then perhaps not unbelievable that the authors of Exile decided to move onto such different platforms as opposed to remaining with newer Acorn hardware. As Peter Irvin says:

I moved from the BBC to the C64 rather than the Archimedes because the market was bigger - i.e. global.

The features

With the passage of time, relatively long in the computer field, games and their source code become lost or hard to find and memories become hazy of old projects. I understand though that Exile is still available to order from Audiogenic's as detailed on their web-pages. In addition I have been fortunate enough to talk to Peter about the conversions and to another member of the conversion team.

Versions exist for the Amiga 500 and 600 and a version with 'vastly superior graphics' for the A1200. Apparently the gameplay remains the same in each version. I was surprised to hear that the A1200 version (known as the AGA version) was released as an 'update' to the first Amiga version in 1995 so Exile as a project— disregarding any current plans— initially spanned around 7 or so years as a project!

First I'll let Peter Irvin describe the 16-bit versions:-

The 16bit versions had superior graphics, animations, and sound, as you'd expect. The game had more detail throughout and whilst the map layout was similar it did have extra areas with more puzzles (e.g. the spiders). With the huge increase in Ram over the 8 bit versions the terrain could afford more variation which made the underground areas much more realistic than the 45degree passages before.

To illustrate some of this, I have been able to get hold of a couple of screenshots from the first and subsequent,enhanced Amiga versions. Anyone familiar with the BBC version will undoubtedly recognise the locations depicted.

For further images from these incarnations of the game T.R.Schmidt has allowed me to show some images which can be found on his site as well as on my Amiga image page. Also on this page are images from the Hall of Light Amiga games database brought to my attention by Conrad TM (Deadly Cookie).

Further features I am told the Amiga version included are messages such as:

It has given you special powers
She wants you badly(!)
Serendipity
Food not for you but for what?

I assumed these are clues appeared at defined points in the game or maybe occasionally (like Triax or the robots appearing). As the sender of this information speculates, "perhaps William Reeve would know for sure". I would be surprised if they were superfluous and didn't appear at all but were not removed as this does not seem consistent with the authors' usual efficiency of programming. However, I'm told that they these messages only appear when the game has been hacked to reveal extra otherwise unseen objects (!) indicating, perhaps, that they were messages that were intended for objects that the authors didn't have time to add.

I've now added a new subsection to deal with these quirks and other unusual accounts of playing the game.

T.R.Schmidt who runs the Exile Resurrection Site reveals many of the extra features in his amusing commentary and plentiful screenshots on his site.
In addition to various new and enhanced Pheobus creatures (e.g. the clam and the rabbit), there are features depicted such as meteors bombarding the planet.

I've added clips from the graphics files from both the AGA version and ECS versions of the game. It's interesting to see that the graphics are, as with the classic BBC version, stored in a very compact manner although presumably with less multiple usage and processing as the files are much larger and diverse as can be seen on the Amiga images page.

A quick note from Peter about the graphics files:

The sprites look very much all individual - ie non-overlapping. In
retrospect for this version it might have been better to have them as
separate files - though less easy to work with - a hangover from the BBC
version.
I think Herman Serrano did these [Amiga update graphics],
as well as most of the other Amiga graphics - but I'm not 100% sure.
That version almost didn't come out at all since whilst I was finishing
it off I was burgled at home but fortunately the machine with lid off
and strange wires dangling out didn't look too appealing to the burglar.

Also on the Resurrection site is the Amiga Novella. I'm not sure if it is an introduction to the game as found in the BBC version's manual or an extract from another novella but it appears to be a re-write of the original story perhaps tailored to the spirit that the authors thought was appropriate to the later conversions

The 16-bit versions were all improved in this way beyond the original BBC version. From the perspective of a player of the BBC version it is interesting to hear of extra areas and features that were added not to mention the improved visual and audio features!

Sound

On the subject of the sound, ConradTM has extracted the sound from the game as WAV files. They appear to be samples or high-quality synthesized sounds. Being a fan of the BBC Micro I'm not sure if anything could ever come close to rivalling the ingenuity and originality of the sound on that version given the limitations of the machine but the Amiga samples are certainly more realistic as they are. However, I don't know if they were utilised in the same way as the BBC Micro's sounds for example the imps sounding more agitated and making longer bursts of noise as you imposed on them more. Also sampled sound was used for the robots and Finn (again in different lengths according to severity of injury).

Another addition to the team

In order to convert to the 16-bit machines Peter and Jeremy 'hired an Exile fan' by the name of William Reeve. To those with a long and detailed memory they will recognise the name as that of the co-author of the well-received BBC game Pipeline. Here William describes the background to his involvement:

I had finished a game called Pipeline with Ian Holmes at the same time as Peter and Jeremy finished Exile - I was 15/16 at the time, Ian was a year younger! We went to London for a publicity trip together. I remember that Pipeline made a fantastic impression on the press (it was the first game to get 5 10s from Micro User - beating Exile to the same honour by one month). But Exile made a fantastic impression on me. On the way home on the train I grilled Peter and Jeremy about its various accomplishments on the technical side. What they let slip out of their tight lips was enough to make me
amazed.
I stayed in touch with Peter and Jeremy. By this time I was quite into the Amiga, and hassling P&J to do a conversion. They said "why don't you do it?". This was a challenge I was very excited by.

William could see that the advantages of the Amiga were potentially numerous as far as a conversion of Exile was concerned but the difference between the 8-bit BBC and the Amiga presented a significant challenge:

Superficially, the Amiga was a brilliant machine for Exile. It had hardware supported scrolling, 16 colours simultaneously, sprites, blitters, 512k of memory etc. However in fact it was a difficult job. Exile was perfectly suited to the BBC architecture and forcing it onto the Amiga was a bit like trying to fly drive a kitcar on an Autobahn.

The Amiga had an architecture which very often assisted highly graphical games and the number of games released on the platform is perhaps a testament to that. However, at least the first releases of the computer were not blessed with significant processor speed above that of their 8-bit predecessors. This proved to be one of a number of difficulties:

Everything on the Amiga turned out to be quite a difficult job. For
example:
- Full flexible four-way scrolling had actually never been done before on the Amiga - most scrolling is unidirectional, with people prepared to take a hit on processing power. We were the first fully flexible hardware-supported scrolling system. Though it looked great, it was a bitch to perfect.
- Our graphics skills weren't really up to the job. Peter was a pretty dab hand in 3 colours at 160x256 resolutions. But less good at 16 colours in 320x256 resolution
- Memory, bizarrely, became a big problem. By doubling the number of colours and the resolution you need four times as much memory for graphics. Plus the screen took about 100k of memory. Plus the sound was now properly sampled - requiring more memory. Plus 68000 code isn't as efficient, requiring at least twice as much memory as the 6502 version. And so on and so on
- Improvements. It was so difficult faithfully converting the original that we didn't put any effort into adding improvements.[ I assume William refers to the A500 and A600 versions here then? ˜ AW]

...The 6502 is, to this day, an incredibly efficient processor and Exile exploited it to the hilt. So moving onto the 68000 architecture, which was designed to support certain tasks very effectively but was less of a general-purpose all-rounder, meant that we were in a hostile environment and didn't make anything like the same impact.

Exile was nevertheless, an acclaimed game on the Amiga as it was on the BBC. The final version, regardless of version and what was going on 'beneath the bonnet' was surely then an impressive product:

Nonetheless, we produced a playable version of Exile that was at least as good as the original - and much more professional looking. This was done over a summer [3 months, in my bedroom], and to that end I think we achieved a lot.

The 1995 update

The Amiga AGA ('Advanced Chip-set') meant that a greater graphics capability was on offer for this platform and an update to the earlier Amiga version was duely released. For this version, yet another individual was hired by Peter, Tony Cox.

Tony's first reaction when given the job was to the legacy of the game's origins:

I remember being seriously impressed with all the stuff that was done to
squeeze the game into the tiny memory available. Even on the Amiga,
there were still some legacy from the way things worked on the BBC (the
sourcecode even had comments which referred to the original 6502
assembly code in places)

The AGA version is visibly different, taking advantage of a larger pallete and faster CPU. Tony describes the job required in doing this, adding other enhancements characteristic of the game and other bits and pieces:-

First job on converting to the AGA chipset was to make it work at all.
There was some self-modifying code which didn't work because of the
instruction cache on the newer CPU in the A1200. We had to narrow down
the bits that were failing with the cache enabled, and fix them. With
that out of the way we turned to the graphics engine. William did a lot
of the work updating the engine to use the bigger graphics (each cell
was 48x48 instead of 32x32) and deeper palette. I added the layer of
parallax using the wider sprites that were available (we also used
sprites for the HUD), and did a bunch of work on some minor graphical
things like particles, font renderer, and some of the tools we used (the
sprite/tile tool was pretty cool). The game code mostly stayed the same, I think there
were a few minor bug fixes, and triggers for some extra sound effects we
squeezed in.

It goes without saying that the task did not go entirely without a hitch:-

It wouldn't build on my usual assembler
(GenAm) because of too much macro voodoo [I know what Macros are but Voodo?! - AW], so we had to use ArgAsm.
ArgAsm was a great assembler, very fast, but a little on the buggy side.
In fact, it sometimes just got stuff wrong, but could be persuaded to
change it's behavior if you rejigged your code a little - so what we did
was have a macro called MUCKED which inserted a couple of nops in your
code at random points depending on a switch, and every time it looked
like ArgAsm was screwing up we'd toggle the switch, the pattern of nops
would change, and it would work again!

According to Tony, Peter's and William's programming was as useful as it was evident:-

For its time, Exile had fairly good structure internally. The game code
was separated from the renderer, and one could almost describe the game
code as 'object oriented' (to the extent that a bunch of macro laden
assembly can be). The debugging stuff that Peter and William had built
in was also solid - it could do symbolic stack and register dumps, and
the game would checksum itself to detect various errors in the debug
build. Certainly made my job a lot easier.

Tony gives an interesting insight into the intensive period in which the update was written:-

My main memory of the experience was just the weirdness of the whole
thing. I was just about to go to college at the time (or was it a
holiday during my first year?), and did most of the work in my bedroom
or my parents' basement, driving over to see William every now and then
with a stack of floppy disks or a hard drive in tow so we could exchange
pieces of code (no version control in those days!). I guess it must have
had a lasting effect though, because I went on to work at Bullfrog, and
thence Microsoft, where I worked on DirectX stuff for a while, before
moving on to be the development lead for a new Xbox game.

The reception

For the reception to this version, I asked on the Amiga games newsgroup and the maintainer of the Amiga Games Database, Angus Manwaring was able to help:-

I've got a little info for you. There were 2 Amiga versions, the ECS one
and the AGA version. A lot of people seem to prefer the earlier version,
and I'd probably include myself with that.
Looking on the extremely useful A-Z of Amiga Games CD by Cameron Lister,
the ECS version got only 68% (1991). The AGA version (1995) got 88%. There
was also a CD32 version which I would expect to be very close to the AGA
floppy version.

A fan's review of the Amiga conversion is present on Angus' Amiga Games Database and you are referred their for a more detailed, subjective account.

The incongruence between most peoples' apparent preference for the earlier version is not reflected in another magazine review reported by Norwegian-based fan Joachim Froholt:-

The One Amiga reviewed both the AGA and the original version in May
1995.
The AGA version got 86 %
The original got 90 %
Matt Broughton reviewed both titles, and the review of the original
began with "My God! This is good. How on earth did I manage to miss this
first time around?"

Joachim has quoted this review from the now defunct magazine which ceased publication after June 1995. It is available to review here.

In summary then, despite difficulties with 'foreign' hardware, it seems that an equally impressive product overall was released onto the Amiga market. It is good to know that the Acorn machine had once again spawned a product which was eventually released to a much wider market and largely was extremely well-received.